1. Field of the Invention
This invention relates to a workpiece positioning device and, more particularly, to a positioning device for the fabrication of compressor impellers.
2. Description of Related Art
Multi-axis workpiece positioning devices or manipulators have recently gained acceptance as a highly efficient apparatus for executing complex motions on relatively inaccessible areas in performing welding or cutting operations. In the fabrication of complex parts, which can encompass two-dimensional and three-dimensional part designs, the conventional two or three axes tilt-rotate positioner typically requires multiple setups and special fixturing in order to obtain proper joint positioning for welding of parts. This method relies heavily upon a highly skilled welder in order to achieve consistently high quality welds.
Recently, automatic or robotic welders have been used in conjunction with workpiece positioning devices to negotiate the workpiece in order to weld difficult part shapes. The complexity of the equipment associated with a robotic welder that can negotiate difficult part shapes is oftentimes cumbersome and expensive. Conventional multi-axis workpiece manipulators are disclosed in U.S. Pat. Nos. 4,402,234 and 3,665,148.
It is desirable to have a workpiece positioning device that has multi-axis capabilities for positioning a workpiece in the best possible orientation, thus enabling a torch, even one that is fixed in place, to be positioned to produce the most favorable angle between a torch centerline and a welding surface of the workpiece. This would result in the elimination of additional torch equipment required to negotiate difficult part shapes.